Nothing like a cool, windy say in the stand to get you thinking. What is the most effective insulation for clothing?

Not really a backpack hunting specific question, but related. IMO the greatest test of insulation from purely a warmth perspective is the treestand. I am interested in creating a combination of clothes to stay warm in a stand, but not have too much bulk that makes shooting a bow problematic. I also have to hike in a mile or so to some stands.

Right now, I have a bottom layer of First Lite merino wool, then a warm wool sweater, a Cabela's primaloft jacket, Kuiu DCS guide jacket and then I can top it off with a Cabela's Predator® Camo Performance Fleece Jacket with wind block. This works pretty well, but what other options are out there? If the temps are around freezing and the wind is not strong I don't need the fleece. The DCS jacket is compressing the primaloft, I wonder if a looser fit would help retain heat?

What are those of you up north doing to stay warm?